[Noob]

Okay, thanks. I don't have as much time as I'd like to right now to look at it, (and this is just a guess) but it looks like some of the data in your model is stored in splines which may or may not be 'seen' by AC3D (Would need to be confirmed by Andy, but since AC3D doesn't currently support working with splines I doubt it can import them). I tried opening the file in Blender too, but it didn't work any better. I don't have any Adobe or Autodesk software currently installed so I can't check them, but I have a feeling that it would open properly there.

As for getting it to work, can you convert the splines to a polygonal 3d object in AI before exporting it? I think that AC3D would most likely be able to see it if you did that. If you have access to a copy of 3DS MAX or the like you could also import it there and then export to 3ds or obj and then use that in AC3D.

Another good thing to try would be to just export a simple box from AI and see if AC3D can open that.